DI-39
Key Design Points
TRANSFORMER PARAMETERS
• Use of foil for the 3.3 V and 5 V windings also helps to
optimize cross-regulation.
• Optional capacitor C7 is the “soft-finish” capacitor and
prevents overshoot on startup.
EEL25
Core Material
Himag MZ4 EEL25.4, Taiwan AL of
344 nH/T2
Bobbin
EEL25 Vertical 14 Pins
• Compact layout for components D7, D10, D11, C11,
C12, C15 will improve cross-regulation and efficiency.
Compact layout for L2, L3, L4, C17, C18, and C20 will
achieve best output ripple.
• Figure 2 shows conducted EMI at 230 VAC full load, with
output“ArtificialHand”grounding. Floatingoutputreturn
gives lower results.
Shield: 32T x 2 x 32 AWG
Primary: 64T x 2 x 32 AWG
Bias: 10T x 4 x 32 AWG
Shield: 2T x 8 x 32 AWG
+3.3V: 4T x foil 0.052 x 14 mm
+5V: 1T x foil 0.052 x 14 mm
+12V: 4T x 4 x 32 AWG
-12V: 7T x 4 x 32 AWG
Winding Details
• Table 2 shows the cross regulation of the supply over load
for both 115 VAC and 230 VAC.
Shield (NC-5), tape, Primary (1-4), tape,
Bias (7-6), tape, Shield (5-NC), tape,
+12 V (13-8), +3.3 V (11,12-9,10), +5 V
(9-10,13), tape, -12 V (14-11, 12), tape
Winding Order
(Pin Numbers)
80
70
Primary Inductance
(Pins 1-4 all others
open)
1.42 mH ±10% at 132 kHz
QP
AV
Quasi Peak
60
50
40
Primary Resonant
Frequency
300 kHz minimum
Leakage Inductance
30 µH maximum
30
20
Table 1. Transformer Construction Information.
10
Output Load
Cross Regulation (%)
Range
(%)
Voltage
(V)
0
-10
-20
Average
-4
-3
-2 -1
0
1
2
3
4
3.3
5
12
-12
10-100
10-100
10-100
100
0.15
1.0
10.0
-100.0
MHz
Table 2. Worst Case Cross Regulation at 115 VAC and 230 VAC.
Figure 2. EMI at 230 VAC Full Load with "Artificial Hand"
Grounding of Output.
For the latest updates, visit our Web site: www.powerint.com
Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability.
Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it convey any
license under its patent rights or the rights of others. The products and applications illustrated herein (including circuits external to the
products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign
patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at www.powerint.com.
The PI Logo, TOPSwitch, TinySwitch, LinkSwitch and EcoSmart are registered trademarks of Power Integrations, Inc.
PI Expert is a trademark of Power Integrations, Inc. ©Copyright 2002, Power Integrations, Inc.
EUROPE & AFRICA
Power Integrations (Europe) Ltd.
United Kingdom
SINGAPORE
Power Integrations, Singapore
Republic of Singapore 308900
TAIWAN
WORLD HEADQUARTERS
AMERICAS
Power Integrations, Inc.
San Jose, CA 95138 USA
Customer Service:
Power Integrations
International Holdings, Inc.
Taipei, Taiwan
Phone:
Fax:
Phone:
Fax:
+44-1344-462-300
+44-1344-311-732
Phone:
Fax:
+65-6358-2160
+65-6358-2015
+886-2-2727-1221
+886-2-2727-1223
e-mail: eurosales@powerint.com
e-mail: singaporesales@powerint.com
Phone:
Fax:
+1 408-414-9665
+1 408-414-9765
e-mail: taiwansales@powerint.com
KOREA
JAPAN
e-mail: usasales@powerint.com
Power Integrations
International Holdings, Inc.
Seoul, Korea
Power Integrations, K.K.
Keihin-Tatemono 1st Bldg.
Japan
INDIA (Technical Support)
Innovatech
Bangalore, India
Phone:
Fax:
CHINA
Power Integrations International
Holdings, Inc.
China
Phone:
Fax:
+82-2-782-2840
+82-2-782-4427
Phone:
Fax:
+81-45-471-1021
+81-45-471-3717
+91-80-226-6023
+91-80-228-9727
e-mail: koreasales@powerint.com
e-mail: japansales@powerint.com
e-mail: indiasales@powerint.com
Phone:
Fax:
+86-755-8367-5143
+86-755-8377-9610
APPLICATIONS HOTLINE
World Wide +1-408-414-9660
APPLICATIONS FAX
World Wide +1-408-414-9760
e-mail: chinasales@powerint.com
A
11/02
www.powerint.com
POWERINT [ Power Integrations ]
